As liquid fuel enters a vehicle gasoline tank during fueling, fuel vapors are displaced out of the tank and into the atmosphere. This invention relates to a coupling which includes a cap assembly (female coupling half) which sealingly engages a standard vehicle gasoline tank and a nozzle assembly (male coupling half) which is attached to or is integral with the spout of a hand-held fuel dispensing nozzle. The cap assembly may be adapted to any existing vehicle gasoline tank or it may be installed without an adapter as an integral part of a vehicle gasoline tank.
The nozzle assembly on the spout of the dispensing nozzle couples with the cap assembly of the vehicle gas tank during fueling and provides for fuel vapor recovery directly from the vehicle gasoline tank to the vacuum recovery system. A predetermined pressure differential between the vehicle gasoline tank and the atmosphere is maintained by a vent valve and a vent sleeve in the cap assembly.
It is highly desirable to recover fuel vapor during refueling of a vehicle gasoline tank. Damage to the environment caused by vapor escape to the environment is well documented in U.S. Pat. No. 5,327,943 to Strock et al. issued Jul. 12, 1994. Hydrocarbon vapor release to the atmosphere when exposed to sunlight can react with air contaminants to create ozone.
Fuel costs continue to soar and the present crude oil price exceeds $30.00 per barrel thus making vapor recovery economical. U.S. Pat. No. 4,429,725 to Walker et al. cites a 97.6% recovery of the vapor which would have been emitted (without vapor recovery) but for the use of the ""725 invention.
U.S. Pat. Nos. 5,385,178 and 5,295,521 to Bedi disclose a flat planar surface disposed on a filler cap with the cap being threaded into an existing gasoline tank receptacle. Bedi ""178 and ""521 further disclose two commercially available coupling halves mounted into or on the flat planar surface. The couplings halves mate with commercially available reciprocal coupling halves. One coupling feeds and is connected to a fuel vapor return line and the other coupling feeds and is connected to fuel a supply line. The vapor return line is separate from and independent of the fuel dispensing nozzle.
There are two known vapor recovery systems: balanced pressure systems and vacuum assist systems. Balanced pressure systems use an elastomeric boot or other positive sealing device to engage and seal the fill opening of the tank during refueling. xe2x80x9cThe interior of the boot is connected to a vapor return conduit to the underground storage tank so that hydrocarbon vapors emitted during fueling naturally flow to the storage tank to maintain the pressure balance between the vehicle tank and the storage tank. The vacuum assist differs from the balanced pressure system because it does not require a tight sealing boot or some other positive sealing arrangement with the fill opening or filler pipe of the vehicle tank. Instead, the vapor return conduits are connected through a vapor pump or other vacuum inducing assist device to collect and transport the vapors emitted during fueling to the storage tanks.xe2x80x9d See, the ""943 patent to Strock et al. at column 1, lines 51-69.
Given the high cost of fuel and given the environmental damage caused by fuel vapor in the atmosphere, it is highly desirable to increase the efficiency of the vapor recovery process. An increase in the efficiency of the vapor recovery process will produce a better environment with attendant financial savings. The coupling of the instant invention combines the features of positive sealing and vacuum assist. The nozzle assembly seals against the cap assembly. Passageways in the cap and nozzle assemblies permit fluid and gaseous communication between the vehicle tank and the service station storage tank.
The invention will be better understood when reference is made to the Summary of the Invention, Brief Description of the Drawings, Description of the Invention and Claims which follow below.
A coupling for a fuel storage tank such as a vehicle gasoline tank is disclosed and claimed. The coupling includes a cap assembly (female coupling half) and a nozzle assembly (male coupling half). The cap assembly is sealingly attached to the vehicle gasoline tank and the nozzle assembly is affixed to the spout of a dispensing nozzle. Once attached to an existing gasoline tank the female coupling half (cap assembly) is normally not removed except if maintenance is to be performed. Additionally, the female coupling half (cap assembly) may be removed from the vehicle gasoline tank if the vehicle is being fueled at a nonconforming service station (i.e., one which does not employ the nozzle assembly of the instant invention. The cap assembly includes a body and the body includes a plurality of apertures in communication with the vehicle gasoline tank. A passageway interconnects the plurality of apertures with a plurality of ports. A substantially flush faced valve covers and closes the ports when the cap assembly is not coupled to the nozzle assembly. The valve uncovers and opens the ports when the coupling halves, namely, the cap assembly and the nozzle assembly are coupled together.
The nozzle assembly includes an annular passageway formed by an outer sheath which is concentric with an inner fluid conduit. The nozzle assembly includes a plug mounted and secured partially in the annulus having radial ports therein. A flush faced valve is formed by the plug having ports and a sliding sleeve. The spout of a dispensing nozzle is generally the portion of the nozzle which is distal (remote) from the hand-held portion of the nozzle. Apertures in the outer sheath enable communication between the vehicle fuel tank and the passageway of the nozzle assembly when the coupling halves are coupled together. The passageway of the cap assembly communicates with the vehicle gas tank via apertures. Ports of the cap assembly communicate with the passageway of the cap assembly and with the nozzle assembly via the apertures in the outer sheath of the nozzle assembly when the coupling halves are coupled together.
When the male coupling half (nozzle assembly) and the female coupling half (cap assembly) are uncoupled little or no spillage occurs due to the flush face configuration of the valve in the female half and the flush face configuration of the plug in the male half.
Vapor from a vehicle gasoline tank is displaced during fueling of the vehicle as the volume for the vapor is reduced by incoming fuel. Use of the term xe2x80x9cfuelingxe2x80x9d herein includes the term xe2x80x9crefueling.xe2x80x9d When vapor is displaced it is directly communicated to a vacuum assisted recovery system. Seals insure that the vapor remains in the passageway of the coupling halves and does not migrate to the atmosphere. Seals also insure that the liquid gasoline is delivered to the vehicle gasoline tank without fluid or vapor migration to the atmosphere.
When the halves are coupled together vapor recovery is effected utilizing mechanical seals and passageways under the influence of a vacuum. When the halves are uncoupled the cap assembly functions to relieve excess pressure within the vehicle gasoline tank. As liquid gasoline is consumed a vacuum is created within the tank and the cap assembly also functions to add air from the atmosphere into the tank.
It is an object of the present invention to provide a coupling for a vehicle gasoline tank and gasoline dispensing nozzle which maximizes vapor recover from the vehicle gasoline tank.
It is a further object of the present invention to provide a cap assembly which sealingly interconnects with a vehicle gasoline tank.
It is a further object of the present invention to provide a cap assembly which includes an adapter enabling interconnection with existing vehicle gasoline tanks.
It is a further object of the present invention to provide a cap assembly which includes a vent valve for relieving pressure when a curtain pressure differential between the interior of a vehicle gasoline tank and the atmosphere is exceeded.
It is a further object of the present invention to provide a cap assembly which includes a vent sleeve for admitting air to the interior of a vehicle gasoline tank when a curtain pressure differential between the atmosphere and the interior of the gasoline tank is exceeded.
It is a further object of the present invention to provide a cap assembly which is small enough to fit within the gasoline cap access door and the vehicle gasoline tank.
It is a further object of the present invention to provide a nozzle assembly affixed to the spout of a dispensing nozzle.
It is a further object of the present invention to provide a low or no spill fuel coupling.
It is a further object of the present invention to provide a cap assembly for the removal of gasoline or other fuel vapor directly from a fuel storage tank through apertures in the cap assembly which interconnect with an annular passageway which, in turn, interconnects with ports.
It is a further object of the present invention to provide a cap assembly which includes a main valve for covering and uncovering ports which interconnect with an annular passageway.
It is a further object of the present invention to provide a cap assembly, or female coupling half, which sealingly couples together with a nozzle assembly, or male coupling half.
It is a further object of the present invention to provide a cap assembly which sealingly couples with a nozzle assembly and which further includes a sealed passageway interconnecting the vehicle gasoline tank and a vacuum source interconnected with a passageway in the nozzle assembly.
It is a further object of the present invention to provide a female coupling half and a male coupling half adapted to interconnect with a vehicle gasoline tank.
It is a further object of the present invention to provide a nozzle assembly which includes a plug having ports for the delivery of liquid when coupled with the cap assembly. The plug is partially press fit into an annular space defined by the inner fluid conduit and the outer sheath of the nozzle assembly.
It is a further object of the present invention to provide a nozzle assembly which has an inner fluid conduit, an outer sheath having a plurality of apertures therein, a plug partially press fit within and tack welded to the fluid conduit and outer sheath, a sliding sleeve affixed to a sleeve guide, and a body.
The invention will be better understood when reference is made to the Brief Description of the Drawings, Description of the Invention and Claims which follow hereinbelow.